Publicação
'A mate or a meal'
| Resumo: | BACKGROUND: Malaria prevalence differs between the two islands that comprise the archipelago of São Tomé and Príncipe. This may be due to differences in the biology of local Anopheles gambiae, the only vector on the islands. Survival rate and feeding frequency are two factors influencing vectorial capacity. Anophelines generally feed just once per gonotrophic (oviposition) cycle. Newly emerged insects, however, may feed two or more times during their first oviposition cycle thus increasing the likelihood of becoming infected. The reasons for multiple feeding are not clearly understood and it is still uncertain whether the behaviour is facultative or obligatory. We, therefore, determined survival and sporozoite rates, and examined the behaviour of An. gambiae from the two islands during their first gonotrophic cycle. METHODS: The wing size of 1,410, abdominal condition of 687, gonotrophic age and mated status of 7,264 female M form An. gambiae collected by light-trap, landing catch, resting outdoors or in copula, was determined from four sites in the archipelago. Sporozoite rates assessed by ELISA in 15,533 females from São Tomé and 2,111 from Príncipe were determined. RESULTS: Estimated survival rates ranged between 0.834-0.849 per day in São Tomé and 0.801-0.818 per day in Príncipe. Sporozoite rates of 0.63% in São Tomé were significantly higher than the 0.24% from Príncipe. Overall 49% of females mated on the second night after emergence before feeding, and 51% on the third night and thus fed before mating. The likelihood of mating before feeding increased with wing size. None of the 3,776 parous insects collected showed evidence of recent mating. All but two of the 198 females collected in copula had undeveloped ovaries. Mean wing sizes and the number of insects collected in a sentinel light-trap varied but the proportion of newly emerged insects in the collection did not. The estimated survival rate of the smallest insects was lower than other size groups, but the overall size distribution of each age group was normal. Parous insects were gonotrophically concordant. CONCLUSION: Differences in mosquito survival contributed to the lower sporozoite rates and endemicity of malaria on Príncipe compared to São Tomé. On both islands all newly emerged insects blood fed on the second night following emergence but only became gonotrophically active on the third night after emergence. Smaller insects had a higher 'mortality/emigration' rate than larger ones. We suggest that insufficiency of Juvenile Hormone until the third day of adult life is responsible for gonotrophic inactivity and that by partitioning mating between the second or third day after emergence females maximise their chances of out-crossing. |
|---|---|
| Autores principais: | Charlwood, J. Derek |
| Outros Autores: | Pinto, Joao; Sousa, Carla A.; Ferreira, Conceicao; Petrarca, Vincenso; Rosário, Virgilio Estólio do |
| Assunto: | Ecology, Evolution, Behavior and Systematics Insect Science Infectious Diseases SDG 3 - Good Health and Well-being SDG 15 - Life on Land SDG 10 - Reduced Inequalities |
| Ano: | 2003 |
| País: | Portugal |
| Tipo de documento: | artigo |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Universidade Nova de Lisboa |
| Idioma: | inglês |
| Origem: | Repositório Institucional da UNL |
| _version_ | 1868984146388320256 |
|---|---|
| author | Charlwood, J. Derek |
| author2 | Pinto, Joao Sousa, Carla A. Ferreira, Conceicao Petrarca, Vincenso Rosário, Virgilio Estólio do |
| author2_role | author author author author author |
| author_facet | Charlwood, J. Derek Pinto, Joao Sousa, Carla A. Ferreira, Conceicao Petrarca, Vincenso Rosário, Virgilio Estólio do |
| author_role | author |
| contributor_name_str_mv | Centro de Malária e outras Doenças Tropicais (CMDT) Instituto de Higiene e Medicina Tropical (IHMT) Unidade de Parasitologia e Microbiologia Médicas (UPMM) BioMed Central (BMC) RUN |
| country_str | PT |
| creators_json_txt | [{\"Person.name\":\"Charlwood, J. Derek\"},{\"Person.name\":\"Pinto, Joao\"},{\"Person.name\":\"Sousa, Carla A.\"},{\"Person.name\":\"Ferreira, Conceicao\"},{\"Person.name\":\"Petrarca, Vincenso\"},{\"Person.name\":\"Rosário, Virgilio Estólio do\"}] |
| datacite.contributors.contributor.contributorName.fl_str_mv | Centro de Malária e outras Doenças Tropicais (CMDT) Instituto de Higiene e Medicina Tropical (IHMT) Unidade de Parasitologia e Microbiologia Médicas (UPMM) BioMed Central (BMC) RUN |
| datacite.creators.creator.creatorName.fl_str_mv | Charlwood, J. Derek Pinto, Joao Sousa, Carla A. Ferreira, Conceicao Petrarca, Vincenso Rosário, Virgilio Estólio do |
| datacite.date.Accepted.fl_str_mv | 2003-05-07T00:00:00Z |
| datacite.date.available.fl_str_mv | 2021-05-06T22:40:27Z |
| datacite.date.embargoed.fl_str_mv | 2021-05-06T22:40:27Z |
| datacite.rights.fl_str_mv | http://purl.org/coar/access_right/c_abf2 |
| datacite.subjects.subject.fl_str_mv | Ecology, Evolution, Behavior and Systematics Insect Science Infectious Diseases SDG 3 - Good Health and Well-being SDG 15 - Life on Land SDG 10 - Reduced Inequalities |
| datacite.titles.title.fl_str_mv | 'A mate or a meal' pre-gravid behaviour of female Anopheles gambiae from the islands of São Tomé and Príncipe, West Africa |
| dc.contributor.none.fl_str_mv | Centro de Malária e outras Doenças Tropicais (CMDT) Instituto de Higiene e Medicina Tropical (IHMT) Unidade de Parasitologia e Microbiologia Médicas (UPMM) BioMed Central (BMC) RUN |
| dc.creator.none.fl_str_mv | Charlwood, J. Derek Pinto, Joao Sousa, Carla A. Ferreira, Conceicao Petrarca, Vincenso Rosário, Virgilio Estólio do |
| dc.date.Accepted.fl_str_mv | 2003-05-07T00:00:00Z |
| dc.date.available.fl_str_mv | 2021-05-06T22:40:27Z |
| dc.date.embargoed.fl_str_mv | 2021-05-06T22:40:27Z |
| dc.format.none.fl_str_mv | application/pdf |
| dc.identifier.none.fl_str_mv | http://hdl.handle.net/10362/117232 |
| dc.language.none.fl_str_mv | eng |
| dc.rights.none.fl_str_mv | http://purl.org/coar/access_right/c_abf2 |
| dc.subject.none.fl_str_mv | Ecology, Evolution, Behavior and Systematics Insect Science Infectious Diseases SDG 3 - Good Health and Well-being SDG 15 - Life on Land SDG 10 - Reduced Inequalities |
| dc.title.fl_str_mv | 'A mate or a meal' pre-gravid behaviour of female Anopheles gambiae from the islands of São Tomé and Príncipe, West Africa |
| dc.type.none.fl_str_mv | http://purl.org/coar/resource_type/c_6501 |
| description | BACKGROUND: Malaria prevalence differs between the two islands that comprise the archipelago of São Tomé and Príncipe. This may be due to differences in the biology of local Anopheles gambiae, the only vector on the islands. Survival rate and feeding frequency are two factors influencing vectorial capacity. Anophelines generally feed just once per gonotrophic (oviposition) cycle. Newly emerged insects, however, may feed two or more times during their first oviposition cycle thus increasing the likelihood of becoming infected. The reasons for multiple feeding are not clearly understood and it is still uncertain whether the behaviour is facultative or obligatory. We, therefore, determined survival and sporozoite rates, and examined the behaviour of An. gambiae from the two islands during their first gonotrophic cycle. METHODS: The wing size of 1,410, abdominal condition of 687, gonotrophic age and mated status of 7,264 female M form An. gambiae collected by light-trap, landing catch, resting outdoors or in copula, was determined from four sites in the archipelago. Sporozoite rates assessed by ELISA in 15,533 females from São Tomé and 2,111 from Príncipe were determined. RESULTS: Estimated survival rates ranged between 0.834-0.849 per day in São Tomé and 0.801-0.818 per day in Príncipe. Sporozoite rates of 0.63% in São Tomé were significantly higher than the 0.24% from Príncipe. Overall 49% of females mated on the second night after emergence before feeding, and 51% on the third night and thus fed before mating. The likelihood of mating before feeding increased with wing size. None of the 3,776 parous insects collected showed evidence of recent mating. All but two of the 198 females collected in copula had undeveloped ovaries. Mean wing sizes and the number of insects collected in a sentinel light-trap varied but the proportion of newly emerged insects in the collection did not. The estimated survival rate of the smallest insects was lower than other size groups, but the overall size distribution of each age group was normal. Parous insects were gonotrophically concordant. CONCLUSION: Differences in mosquito survival contributed to the lower sporozoite rates and endemicity of malaria on Príncipe compared to São Tomé. On both islands all newly emerged insects blood fed on the second night following emergence but only became gonotrophically active on the third night after emergence. Smaller insects had a higher 'mortality/emigration' rate than larger ones. We suggest that insufficiency of Juvenile Hormone until the third day of adult life is responsible for gonotrophic inactivity and that by partitioning mating between the second or third day after emergence females maximise their chances of out-crossing. |
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| eu_rights_str_mv | openAccess |
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| fulltext.url.fl_str_mv | https://run.unl.pt/bitstreams/b7cd8e50-3294-40f7-b0cc-baaffc1f23f4/download |
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| identifier.url.fl_str_mv | http://hdl.handle.net/10362/117232 |
| inst_facet_str | urn:organizationAcronym:unl{{{_:::_}}}Universidade Nova de Lisboa |
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| institution | Universidade Nova de Lisboa |
| instname_str | Universidade Nova de Lisboa |
| language | eng |
| network_acronym_str | run |
| network_name_str | Repositório Institucional da UNL |
| oai_identifier_str | oai:run.unl.pt:10362/117232 |
| organization_str_mv | urn:organizationAcronym:unl |
| person_str_mv | Charlwood, J. Derek Pinto, Joao Sousa, Carla A. Ferreira, Conceicao Petrarca, Vincenso Rosário, Virgilio Estólio do |
| publishDate | 2003 |
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| reponame_str | Repositório Institucional da UNL |
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| spelling | engenBACKGROUND: Malaria prevalence differs between the two islands that comprise the archipelago of São Tomé and Príncipe. This may be due to differences in the biology of local Anopheles gambiae, the only vector on the islands. Survival rate and feeding frequency are two factors influencing vectorial capacity. Anophelines generally feed just once per gonotrophic (oviposition) cycle. Newly emerged insects, however, may feed two or more times during their first oviposition cycle thus increasing the likelihood of becoming infected. The reasons for multiple feeding are not clearly understood and it is still uncertain whether the behaviour is facultative or obligatory. We, therefore, determined survival and sporozoite rates, and examined the behaviour of An. gambiae from the two islands during their first gonotrophic cycle. METHODS: The wing size of 1,410, abdominal condition of 687, gonotrophic age and mated status of 7,264 female M form An. gambiae collected by light-trap, landing catch, resting outdoors or in copula, was determined from four sites in the archipelago. Sporozoite rates assessed by ELISA in 15,533 females from São Tomé and 2,111 from Príncipe were determined. RESULTS: Estimated survival rates ranged between 0.834-0.849 per day in São Tomé and 0.801-0.818 per day in Príncipe. Sporozoite rates of 0.63% in São Tomé were significantly higher than the 0.24% from Príncipe. Overall 49% of females mated on the second night after emergence before feeding, and 51% on the third night and thus fed before mating. The likelihood of mating before feeding increased with wing size. None of the 3,776 parous insects collected showed evidence of recent mating. All but two of the 198 females collected in copula had undeveloped ovaries. Mean wing sizes and the number of insects collected in a sentinel light-trap varied but the proportion of newly emerged insects in the collection did not. The estimated survival rate of the smallest insects was lower than other size groups, but the overall size distribution of each age group was normal. Parous insects were gonotrophically concordant. CONCLUSION: Differences in mosquito survival contributed to the lower sporozoite rates and endemicity of malaria on Príncipe compared to São Tomé. On both islands all newly emerged insects blood fed on the second night following emergence but only became gonotrophically active on the third night after emergence. Smaller insects had a higher 'mortality/emigration' rate than larger ones. We suggest that insufficiency of Juvenile Hormone until the third day of adult life is responsible for gonotrophic inactivity and that by partitioning mating between the second or third day after emergence females maximise their chances of out-crossing.application/pdfen'A mate or a meal'Subtitleenpre-gravid behaviour of female Anopheles gambiae from the islands of São Tomé and Príncipe, West AfricaCharlwood, J. DerekPinto, JoaoSousa, Carla A.Ferreira, ConceicaoPetrarca, VincensoRosário, Virgilio Estólio doCentro de Malária e outras Doenças Tropicais (CMDT)Instituto de Higiene e Medicina Tropical (IHMT)Unidade de Parasitologia e Microbiologia Médicas (UPMM)BioMed Central (BMC)HostingInstitutionOrganizationalRUNe-mailmailto:run@unl.ptrun@unl.ptISSNIsPartOf1475-2875URNIsPartOfPURE: 3299202URNIsPartOfPURE UUID: 7745e383-d6f8-4c64-aaeb-c780421f2f73URNIsPartOfPubMed: 12801421URNIsPartOfORCID: /0000-0001-8572-7708/work/63725339URNIsPartOfPubMedCentral: PMC161788URNIsPartOfWOS: 000184708800003DOIIsPartOf10.1186/1475-2875-2-92021-05-06T22:40:27Z2003-05-072003-05-07T00:00:00ZHandlehttp://hdl.handle.net/10362/117232http://purl.org/coar/access_right/c_abf2open accessEcology, Evolution, Behavior and SystematicsInsect ScienceInfectious DiseasesSDG 3 - Good Health and Well-beingSDG 15 - Life on LandSDG 10 - Reduced Inequalities342952 bytesliteraturehttp://purl.org/coar/resource_type/c_6501journal articlehttp://purl.org/coar/access_right/c_abf2application/pdffulltexthttps://run.unl.pt/bitstreams/b7cd8e50-3294-40f7-b0cc-baaffc1f23f4/download |
| spellingShingle | 'A mate or a meal' Charlwood, J. Derek Ecology, Evolution, Behavior and Systematics Insect Science Infectious Diseases SDG 3 - Good Health and Well-being SDG 15 - Life on Land SDG 10 - Reduced Inequalities |
| status | SINGLETON |
| subject.fl_str_mv | Ecology, Evolution, Behavior and Systematics Insect Science Infectious Diseases SDG 3 - Good Health and Well-being SDG 15 - Life on Land SDG 10 - Reduced Inequalities |
| title | 'A mate or a meal' |
| title_full | 'A mate or a meal' |
| title_fullStr | 'A mate or a meal' |
| title_full_unstemmed | 'A mate or a meal' |
| title_short | 'A mate or a meal' |
| title_sort | 'A mate or a meal' |
| topic | Ecology, Evolution, Behavior and Systematics Insect Science Infectious Diseases SDG 3 - Good Health and Well-being SDG 15 - Life on Land SDG 10 - Reduced Inequalities |
| topic_facet | Ecology, Evolution, Behavior and Systematics Insect Science Infectious Diseases SDG 3 - Good Health and Well-being SDG 15 - Life on Land SDG 10 - Reduced Inequalities |
| url | http://hdl.handle.net/10362/117232 |
| visible | 1 |